Abstract 351: Predictors of Delays to Antihypertensive Medication Initiation Among Young Adults with Regular Primary Care Use

Abstract

Background: In the U.S., young adults (18-39 years old) continue to have low rates of hypertension control (38%) compared to middle-aged and older adults (54%). Although lifestyle modification counseling is a critical step in hypertension treatment, antihypertensive medication initiation is crucial for young adults who remain hypertensive, especially with Stage 2 hypertension (≥160/100 mmHg). However, young adults have low rates of antihypertensive medication initiation and the factors driving delays in medication initiation among young adults who are regular users of primary care are not well understood. The purpose of this study is to compare the rates of antihypertensive medication initiation among age groups and determine predictors of delays in antihypertensive medication initiation among young adults. Methods: This is a retrospective analysis of 14,974 patients, ≥18 years old, receiving regular primary care in a large, Midwestern, academic group practice from 2008 - 2011. Patients were included upon meeting JNC7 clinical criteria for Stage 1 (≥140-159/90-99 mmHg) or Stage 2 hypertension and followed up to 4 years. Patients with a previous antihypertensive prescription were excluded. Cox proportional hazard models (HR; 95% CI) stratified by hypertension stage, were fit overall and separately for young adults 18-39 years old to identify predictors of delays in antihypertensive medication initiation. Results: After 4 years, 51% overall (4,149 of 8,125) were prescribed antihypertensive medication and 69% (1,650 of 2,403) among those with Stage 2 hypertension; 43% of hypertensive young adults (18-39 yrs; 846 of 1,988) were prescribed medication, 62% (339 of 547) among those with Stage 2. Among age groups, 43% of 18-39 year olds (846 of 1,988) received antihypertensive treatment within 4 years, compared to 53% (40-59 yrs; 2,223 of 4,216) and 56% (≥60 yrs; 1,080 of 1,921). Adjusting for patient factors, blood pressure lability (i.e., intermittently normal blood pressures), and provider factors, adults 18-24 years old had a 50% slower rate of medication initiation (HR 0.5; 0.4-0.7) than ≥60 year olds. Adults 25-31 years (HR 0.6; 0.5-0.7) and 32-39 years (HR 0.8; 0.7-0.9) also had slower rates of medication initiation. When analyses were limited to young adults, higher urgent care use, White race, labile blood pressures, and non-English primary language were associated with slower rates of medication initiation. Young adults with diabetes, Medicaid and more specialty visits had faster rates. Conclusions: There are delays in antihypertensive medication initiation for young adults with multifactorial causes. Addressing poor hypertension control rates among young adults should target key factors related to delays, while continuing lifestyle modification counseling.